645244446613 has 24 divisors (see below), whose sum is σ = 713469529800. Its totient is φ = 583067197440.

The previous prime is 645244446607. The next prime is 645244446619. The reversal of 645244446613 is 316644442546.

It is an interprime number because it is at equal distance from previous prime (645244446607) and next prime (645244446619).

It can be written as a sum of positive squares in 12 ways, for example, as 46784392209 + 598460054404 = 216297^2 + 773602^2 .

It is a de Polignac number, because none of the positive numbers 2^k-645244446613 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645244446619) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3941473 + ... + 4101913.

It is an arithmetic number, because the mean of its divisors is an integer number (29727897075).

Almost surely, 2^645244446613 is an apocalyptic number.

It is an amenable number.

645244446613 is a deficient number, since it is larger than the sum of its proper divisors (68225083187).

645244446613 is a wasteful number, since it uses less digits than its factorization.

645244446613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160969 (or 160956 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 49.

The spelling of 645244446613 in words is "six hundred forty-five billion, two hundred forty-four million, four hundred forty-six thousand, six hundred thirteen".